Method of sending impulses for automatic telephone exchanges



Sept. 13, 1927. 2, 0

.K. HERSEN ET 'AL I METHOD OF SENDING IMPULSES FOR AUTOMATIC TELEPHONE EXCHANGES fluemfors 1,642,202 Sept. 13,1927. K'HE'RSEN ET AL METHOD OF SENDING IMPULSES FOR AUTOMATIC TELEPHONE EXCHANGES V Filed Feb. 4. 1925 2 Sheets-Sheet 2 5 2 5 c m g, 5 S, S; x N N N a? I 1 .2 J

=1 A R F z v l: B

172 van fOAfi Patented Sept. 13, 1927.

UNITED STATES LIN-TEMPELHOF, GERMANY.

PATENT omen.

WULF BIRSCHBERG, OF BERLIN- AKTIENGESEL LSCHAFT, OF BER- METHOD OF SENDING IMPULSES FOR AUTOMATIC TELEPHONE EXCHANGES.

Application filed February 4, 1925 Serial No. 6,735, and in Germany september 30, 1924.

This invention relates to arrangement for automatic telephone eX- changes, more particularly for those of large size in which v largegroups, for instance groups of 400, are particularly important. I v

As is well known, in automatic exchanges of the latter kind it is possible to cmploy directly number dials with ten divisions but only by using a so called register, that is a;

device for translating the impulses sent out by the dial on a decimal basis to a series of impulses corresponding to the grouping of the terminals on another non-decimal basis. Such devices, which as a rule comprise a number of step switches receiving the current impulses sent out by the subscriber, and other switches transmitting the received il11 pulses, as well as control-switches and relays, are always extraordinarily complicated; they render therefore the installationcostly and make it difiicult tokeep up an automaticexchange. p v This invention shows a simple way for attaining the desired object, permitting firstly the use of the usual number dials provided vith only ten digits, which at the same time may also contain letters, and further the direct operation of switches with a great sub; division of the contacts, for instance of switches with twenty steps, so as to obtain large groups of exchanges.-

This is achieved by a duplication (or multiplication) of the possibility of connection in the directionrot the called subscriber but is also further .developed in the sense that the increase in the possibility of connection is extended to all (or several) selection steps. Another teatureot the invention consists in the fact thatthe number (or letter) set in front of the selective number proper, fixes thecombination determining whether. all or several) following selection ;stages' or steps belong to one or another group of selective connections. V

For carrying out the invention,- when using selectors arranged for current impulses, these current inipulses is; quired for the purpose me; be 1 dr- .l d. in "We-emu sof -1. F sa het the :two grjoupstheid gitsl tcf10 a transmitting the advantages of formingend n'g' were.

but they can be differentiated by an added group designation letter A or B.

vTo enable the capacity of any selection stage to be doubled, care must be takento enable each selection digit of the connection number to be rendered operative in two ways, for instance, a selected number 5-4-3 can call up the connection for A A, A in one group, or A, B A in another group, or B A A in yet another group.

According to this kind of subdivision into two group halves A to 10 and B (0 10, in one system for, say, three series of current impulses which each control 2 X 10 outgoing connections that is to say comprise 20 X 20 8000 lines, it is possible to have the following combinations determining whether the connection called belongs to thegroup A or group B; v v

Group halves of the selection stages or Combination.

eps. 1 A' A A 2 A A B 3 i A B A .4 A B B 5 B A A 6 B A B 7 B B A 8 v i B B B Consequently eight combinations are pos sible in this case, It will be seen that in systems for four series of current impulses (160,000.:l1nes), there will be obtainedsixteen combinations, for five series of current impulses (3,200,000 lines) '32 combinations, and so on. (on the contrary in system with only two stages of twenty division selectors only four combinations will be obtained.)

I he basic idea of the invention is firstto fix by a previous selective. operation the combination required for the selectionof'the desired subscriber, and furtherto constructthe first current impulse receiving,device in such a m anner as to. control the-subsequent selective operations so that; the succeeding current impulse series of the desired .kind traveliinthe one or infthe other direction as requiied f. 'v i 4-;1 .fFOI. ngout this process various ways adp d l e es" i i the 1 11? of the present invention, in as far as they utilize this group system.

The apparatus could be arranged in such a manner that the preceding current im- 5 pulse sent produces, according to the so called combination number or combination letter, in the single selection stages, such an operation or control by the switches that the devices they .advance allow the current impulses for each of these stages to become operative in the group half A or in the other half B. The same continued on two stages, allows the action to take place on 2 x 2, that is to say, on the fourfold number of group halves and so on. It is therefore possible, by a previous sending of the combination number, to influence each subsequent current impulse series in such a manner that it shall become operative in one or in the other direction.

In this method of construction, ordinary number dials provided with ten finger holes are used, in which for each number the corresponding number of current interruptions of the loop occurs in the well known manner without the formation of large groups being thereby restricted or the construction of the transmitter complicated. The advantage consists firstly in the use of standard dials, which is also important for trafiic with exchanges working on the old system with groups of 100 moreover, a considerable advance is made compared with the large group systems hitherto known. These have been so arranged up to now that either the selection of a number by the subscriber sets a register which then sets the switches in the single selection stages, or for instance one number dial is used for sending out twenty current impulses. In any case when the connection is made, there are considerable losses of time, either at the exchange owing to the subsequent setting of the switches affected by the register, or at the subscribers station owing to the slower running down of the dials, naturally required in the case of dials with more than ten divisions.

' These losses of time are also eliminated by 6O switch V7 which is advanced one step after each series'of current impulses, comes conthe present invention.

In Figure 1, IV is a switch assumed to be a simple small rotary selector by means of which the desired combinaton is set. The switch W is provided with as many brush arms as there are selection stages, and with as many fixed contacts as there are combinations, the said contacts being either insulated or earthed. For an 8000 system for instance each selector is provided with three brushes and with eight fixed contacts,

which case is illustrated in Figure '1. The

secutively by its arm into contact with the switch arms 7a,, 76,, etc. and influences the sequence of the 5 number selection, according as the switch WV becomes connected to earth or not. The switch W is provided with only one brush arm and with a number of fixed contacts, equal to the number of the selection stages.

In Fig. 2 is shown a modification of the system.

The operation is as follows:

As soon as the subscriber takes off his receiver the current relay in the call finder CF becomes operative through operations which are well known and need not be described here. At the same time, by proper switching operation, the contact 00 connects the contact a, to earth. When the subscriber transmits then the first digit the circuit of magnet D through ml II,, a, and w is repeatedly closed. The relay U which is slow to deenergize also becomes then operative and in its turn operates the second retarding relay T. The switch arms of the selector V. are set by the magnet D on a given contact. After the first digit is sent, the relay U releases and closes, through contact u and the working contact If, a circuit for the magnet D. The latter then becomes operative, and advances the arm /c After the expiration of a certain retardation period. the contact It falls back again and opens the circuit of D so that its armature drops down. As soon as the switch WV leaves the normal position, the contacts ml, and ml are operated. The working contact ml, switches off the magnet D, so that the selector W is no longer influenced by the next following currentimpulse series, whilst the contact ml connects the contact a, to earth, so that at the next digit current impulses are repeated over the contact a, into the a line.

In order to explain how the succeeding sending of impulses is influenced by the currents sent by the previously set combination, the use of a line selector-LS as in Figure 1, is fully set forth, as in the use of such a switch the conditions are more difficult than with the group selectors, since in the line selector action two sets of current impulses become consecutively operative, whilst in the group selectors only one set of current im pulses is required. As will be seen from the drawing of the path of current, the 5 branch of the connection wire to the group or wire selector can be connected through is, consecutively to the single arms 70,, 76 etc. of the selector W and here be'eithe'r insulated or connected to earth, according to the com-' bination set. In the singleselectors, on the 6 side, are provided switch relays, which, according as the b-branch finds earth or not in the selector W eitherbecome operative or remain at rest. In the line selector, as it is a question here of the last two selection stages, there are accordingly provided also two'switch relays Q. "and'Q S to calling up mag-m S are sequence switch contacts which are closed for the: connection of the. indicated selection stages controlled thereby. V

The portion of the diagram to the right of and under the main diagram is a continuation of the latter at the points a, by By Way of example'it willbe assumedflthat the subscriber selects the call mum ber 6M3; that meansthat by the selection of the first digit 6, the 'followingthree digits are hired as B A? and 13 p r r In the. example under consideration let it be va'ssumed that, as soonas, by, th first selective operation, the selector IV is set to thedesired combination (6), and at the same time the arm. is, of the selector W is ad vanced to the first contact, the next selec tion digit has been used for the group selection, (not further described), controlled by the combination arm 70,. Atthe, same time let it be assumed that the selector W with its arm 72, has arrived in the second position, owing to which a is connected to earth through nd whilstat the same time the switch relay Q, connected to the b branch, is either rendered operative or re- Illa 111321 6 rest, according'to the combination. If we consider w the last two selection stages of the line selector in our example, in this case the arm is, of the selector W would be set, for the penultimate current impulse, on the sixth contact (not earthed). In that way there is no clos'ing o'f circuit over 10 and 7a,, and Q remains at rest.

IVhe'n now the current impulses of the penultimate digit- (el) are sent out, the relay Y is operated throughthe sequence switch contact S in the position 1; this relay Y, by means of its contact y over the sequence switch arm S l in the position '1, advances the intermediateselector IS. This selector is intended to transfer its recordlaterto the line selector proper. After the termination of the penultimate current impulses, the switch WV passes over to the thirdfconltact so that the arm k1, when on [0, is earthed in thecase of our example (combination'fi). The .relay Q 'becomes thereforeoperative over the control switch S in the position 2' e and remains locked over the contact q over S mate the end of. theconnection. Then the last digit is being sent, the relay Y again becomes operativeover the seque ce. switch S" and repeats the impulsesby its contact y, the current impulsesover S and thela branch, directly to the connector:

As regards the connection ofthe contacts of the relays Q and Q it is to be understood that the a testing; wire (not shown) would be carriedcorrespondinglyby the contacts of these relayfs, so that in the position of rest of both relays, the connection goes to the connectors of the first hundred; if the relay Q. alone becomes operative, connection is' made to the second hundred, if the relay 7 Q jonly' becomeso 'erative, to the third hundred, whilst ifbo't H relays becomeoperative, the fourth hundred will'be reached. In our example, as the" combination selected is B A N, the" rela Q is not operated, but the relay Q," is. onsequ'ently a connector of the secondhu'ndredfis reached inthe selected 400 gro p.

It will be seentliefrefrom that with'the installat'ionfdesciibedit is possible, as soon as the combination has been fixed by a previous selection, to'sele ct with only two current impulse emissions of al'O division number dial, any igivensubs'criber out of a400 group, with three current emissions out of an 8000 group and so on. As the o era'tionjofthe switch relay takes place 6601 time before the beginning of the current impulse emission, and without any loss of time, the connection is ready immediately after the last current iinpulse emission. Conse' uen'tly the losses of time, suc'h'as' occur 0t ier systemsowing' to the subsequent settingjof the selectors on the frgisterll, are avoided here.

Figure 2 shows a further develo nient of the basic idea. As already stated, t er an installation with threecurrent impulse emis sions (capacity 20 x 20x 20:8000) eightdifferent three place combinations are required.

The installation in such a' case would connations required fo'r8000 lines can be re-, peatedfor' the secondtimeon the' contacts 1"7 20. (In FigiireQ, only the combinations up to 16Yareshown.)" If for instance, the preliminary seIect0r (P S) is utilized, then it is possible, by connecting the testing re- (ex'change lay P of the selectorPS to earth throughthe' I arm t to ensure either that the II VW preliminary selector will mqve tothe leads't-o the one, or the other 8000 group, according- 1y as W is; set 011 ale-firs eightor an the gossihle. to have; oi ht combinations worked yf'fiist selec Itwould therefore b POSSi Fus n fi s g out Selectors ond and third group selectors for operation, whereby extraordinary savingcan be effected by theuse of our invention.

For

secondw eightv contacts. In'each group; it is;

building large exchanges on -th i s;s'ysused.

tem, for each selection stage for selecting large groups, the whole selection possibility of the dial up to the figure can be utilized and in a corresponding manner the addition of the combinations not yet utilized (for instance from the 8th to the 10th or 16th to 20th group) owing to which group units with four selection stages can be formed. Also for larger networks which go beyond a selection stages, it will be possible to build the 100,000 unit on ourcombinat-ion system, whilst for the selection of the first stage an ordinary preliminary selection on the decimal system could be advantageously What we claim is:

1. In a telephone exchange system, subscribers lines, subscribers sets with dials, automatic switches for establishing connections between said lines, multi-position group selector switches, multiple terminal banks for said switches upon a larger base than the decimal one, each bank of terminals being sub-divided in two groups, a relay for each multi-position switch to operate the one or the other of the said two groups, multi position connector switches, multiple terminal banks for the connector switches each sub-divided into four groups, a pair of relays for each connector switch for govern ing the terminal bank thereof, a progressively operating switch with brushes, one for each group select-or and two for each connector, a combination of insulated and earthed contacts upon which the brushes are positioned when the first digit is dialed, means to selectively operate the said relays on the impulses from the second to the last digit of the dial, means to adjust the multiposition switches directly by the dialing impulses, and means for variably controlling said multi-position switches for governing one or another of said connector switch bank groups under the control of the relays dependent upon the first progressively operating switch being positioned for connection with insulated or earthed contacts of said combination of insulated and earthed contacts.

2. In a telephone exchange system, subscribers lines, subscribers sets with dials, automatic switches for establishing connections between said lines, multi-position group selector switches, a multiple terminal bank for each of said switches upon a larger base than the decimal one, each bank of terminals being subdlvided lnto two groups, a relay for each multi-position switch to operate the one or another of said groups, multi-position connector switches, a multiple terminal bank for eachconnector switch, each subdivided into four groups, a pair of relays for each connector switch for governing the terminal bank groups thereof, a progressively oper-- ating switch with brushes one for each group selector and two for each connector, a second progressively operating switch to control the sequence of movements of the brushes of the first progressively operating switch, insulated and earthed contacts upon which the brushes are positioned upon the first digit being dialed, means for selectively operating the relays on the impulses from the second to the last digit of the dial, means to adjust the multi-position switches directly by the dialing impulses, and means for variably controlling the multi-position switches for governing one or another of said connector switch bank groups under the control of the said relays dependent upon the first progressively opera-ting lswitch being positioned for connection with insulated or earthed contacts of said combination of insulated and earthed contacts.

3. In a telephone exchange system, subscribers lines, subscribers sets with dials, automatic switches for establishing connections between said lines, multi-position group selector switches, multiple terminal banks for said switches upon a larger base than the decimal, each bank of terminals being sub-divided in two groups, a relay for each multi-position switch to operate the one or the other of the said two groups, multi-position connector switches, multiple terminal banks for the latter switches each sub-divided in four groups, a pair of relays for each connector switch for governing the terminal bank groups thereoifl'a progressively operating switch with brushes, one for each group selector and two for each connector, a second progressivelyroperating switch to control the sequence of the brushes of the first progressively operating switch, a group of insulated and earthed contacts selectively engaged with the brushes under the firstand second digit impulses of the dial, means to selectively operatethe relays from the third to the last digit ofthe dial,

means to adjust the multi-position switches directlyby the dialing impulses, and means for variably controlling the multi-position switches for governing one or another of said connector switch bank groups under the control of the relays dependent upon the and earthed contacts.

In testimony whereof we have aifixed. our signatures. I

connection of said relays with the insulated KARL HERSEN. WULF HIRSOHBERG. 

